200mm 2.8 L mk2 loose focus barrel

the part im talking about is where the rubber focus grip is attached to. see below for pic, i highlight it with a red box.

i bought a 200mm 2.8 L lens used on craigslist and during my initial testing before buying, the focus barrel/ring worked, like when i turn the focus ring for MF, it worked.

used it for my event, the ring came loose, while spinning the manual focus, it doesnt change anything. i have to grab the end of the focus ring (i highlighted in a green box in the same pic below) for it to manual focus.

it happens intermittent. i dont know if it depends on temperature but sometimes its on there good to where i can use the rubber section to MF.

has this happen to anyone? how much does it cost to get fixed from Canon? or is it possible to fix it myself?

note: photo is not by me, im just using a stock photo from the internet.

HOSTED PHOTO
please log in to view hosted photos in full size.

no one knows?

So does it appear that there is some kind of adhesive problem between the rubber section and the bit below it?

im assuming. something isnt attaching together. not sure if theres a small screw that holds it in place. would it be ok to pull the rubber place to check? im afraid to stretch out the rubber.

I've only done that on an old MF lens and the glue had simply failed, but that was a really old lens unlike yours. I'm not sure how Canon stick the rubber there and whether they even go about hiding any screws underneath the rubber, so no idea sorry. I'd be reluctant.

Never had one do this and I have owned several over the years. Makes me wonder if that is why he sold it?

So, it's not just the rubber that's rotating freely but the entire focusing element?

I don't think there are any screws under the focusing ring like there is with the mki version. I've upped the parts lists for both so you can see what I mean.

@tanglefoot47: i mentioned it to him and he said he didnt even know it was like that since he only use the lens with af.

@emitecaps: thanks for that parts list. so that focusing ring is showing as 1 unit, i wonder if its a 2 piece unit. i slid the rubber grip down the lens and it doesnt have any screws.

where can i find repair manual for canon lens?

polobreaka wrote in post #10413760
where can i find repair manual for canon lens?

You can buy them for $30. Haven't seen any "free" pdfs though.

It sounds like all or part of the focus ring is not properly engaging the focus unit inside.
I wonder how the AF/MF switch engages the manual focus?That would be the most likely area to check.I'm guessing the whole rear end might have to come off to check...
Probably not any elements tho..?